A simple large-scale synthesis of very long aligned silica nanowires

A simple method based on the thermal oxidation of Si wafers has been discovered to provide a large-scale synthesis of very long, aligned silica nanowires. The as-grown product was characterized by scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, and photoluminescence. The obtained SiO2 nanowires had no metal contaminations, ultralong lengths of millimeters, and most diameters of ∼50 nm. The PL spectra of the SiO2 nanowires showed a strong and stable green emission at 540 nm. The nucleation and growth of the SiO2 nanowires were investigated.